About [[MediaWiki:Massmessage-summary-removemulti/en]]

This message is only ever used if $1 is at least 2. The message documentation doesn't explicitly document the possible values of $1, but it does say that it's for removing multiple target pages (same goes for addmulti).

For example, Russian language have multiple plural forms. e.g. MediaWiki:Createacct-benefit-body2/ru.

So singular part should exist to make translation easier.

Made documentation more explicit and submitted a patch.

For the sake of transparance the first account (Skärminspelning) is also me, but whilst doing a screencast.